There are two familiar, contemporary responses to this question. The theist says that the question has an answer and that this answer is that God caused spacetime to begin to exist. The standard response of the atheist is to say that there is no answer to this question; spacetime’s beginning to exist is a brute fact or has no explanation. This standard atheist response seems to give theism a prima facie theoretical superiority to atheism; theists offer a detailed explanatory hypothesis about why spacetime begins to exists, and standard atheists are content to leave spacetime’s beginning to exist unexplained